Grade crossings are locations on a rail line where vehicular traffic crosses the rail line. It is at these grade crossings where there exists a potential of an accident between an approaching train and an obstacle, e.g., a car that became trapped on the grade crossing.
Grade crossings exist in both urban and rural areas, and in some instances are equipped with devices intended to prevent vehicular traffic from occupying the grade crossing just prior to the arrival of approaching train traffic.
Grade crossing protection (GCP) devices are normally fixed installations at crossings with both visual and/or audible signals and physical barriers. Activation of these devices generates signals that warn oncoming vehicular traffic of the impending arrival of a train while barriers block the road to prevent vehicular traffic from occupying the crossing when the train approaches. GCP devices may be connected to transmitting devices along the track so that the train engineer is notified of their activation placing the crossing in a “safe” state thereby allowing the train to proceed into the grade crossing.
Current grade crossing protection systems operate on the principle that if the GCP device is operational, the grade crossing area, protected by the devices, is clear of obstacles. However, it is possible, even with a fully operational GCP device, for a vehicle, or other obstacle, either by accident or by design, to be within the grade crossing as the train approaches, leaving the engineer insufficient time to stop the train, even after detecting the obstruction.